Optical imaging systems typically comprise a detector, usually placed within a housing having an aperture through which the detector may view an external scene, and a telescope that images the external scene onto the detector. Certain optical imaging applications require the ability to scan the field of view of the optical system over a wider field of regard. Existing systems for such application include off-axis telescope designs with flat, fast steering mirrors for scanning. For many applications, the optical subsystem must be as compact as possible, while remaining consistent with required optical performance for high quality imaging. For example, some missile systems require an optical system capable of scanning over small angles with high performance in the infrared spectral bands. Since the diffraction limited imaging resolution is limited by the aperture size, many applications of such missile systems require the aperture to use a very large fraction of the frontal cross-section of the missile in order to achieve good imaging resolution. Therefore, off-axis optical system designs, or on-axis designs that are optically folded using a flat mirror, are not good solutions for such applications.